The Trade Minister Andrew Robb has hit back at critics of the free trade agreement he brokered with Japan earlier this month, saying he's bemused by the 'hysterical' reaction of some agricultural groups.

Some dairy industry leaders were particularly critical of the deal, calling it disappointing and a missed opportunity.

The peak sugar industry body Canegrowers said their members had been hung out to dry in the agreement, while the rice industry said it was disappointed but not surprised to be left out of the Japan deal.